1. Field
The following description relates to a data transmission apparatus and method using a plurality of transmission antennas. More particularly, this description relates to a data transmission apparatus and method of generating a precoding matrix based on quantized channel state information and transmitting data using the precoding matrix.
2. Description of the Related Art
Currently, research is being conducted to provide various multimedia services, such as voice services in a radio communication environment, and to support data transmission with a relatively high quality and high speed. As a part of these studies, there has been a study for a data transmission system with multiple transmitting/receiving antennas using a spatial-domain channel. A data transmission technique using multiple transmitting/receiving antennas may use multiple antennas at both ends of a transceiver to increase a channel capacity within the limited frequency resources, thereby obtaining a high data transmission rate.
Since a transceiver using a data transmission technique with open loop multiple transmitting/receiving antennas does not require channel information, the transceiver may be configured with a relatively simple structure without wasting an uplink radio resource. However, where a spatial correlation of the channel increases, or multiple channels undergo deep fading due to difficulties in adaptively coping with changes of the channel, performance of the transceiver may significantly deteriorate.
A transceiver using a data transmission technique with multiple closed loop transmitting/receiving antennas may transmit data using channel information transmitted from a terminal. In this instance, data transmission performance is significantly improved because characteristics of the channel are applied to the transceiver. However, a base station apparatus may receive only quantized channel state information due to limitations of the bandwidth of an uplink from the terminal to the base station apparatus. The base station apparatus may not receive accurate channel state information due to quantization noise generated in a quantization process. Due to quantization noise, an accurate precoding matrix may not be computed and data transmission performance may deteriorate.